Anthropology, Wichita State University
Thursday All day, Plaza Level
This study examines the presence and extent of quantifiable sexual dimorphism in the 12th thoracic vertebra, and explores the effects of age on morphological variation and sex estimation. Temporal variation and secular effects are also evaluated in order to address non-genetic alterations and influences on the skeletal morphology. The 12th thoracic vertebra, femur and sacrum of 168 (94 males and 74 females) mature South African Blacks from the Raymond Dart Collection (University of the Witwatersrand, Johannesburg, South Africa) and 407 (205 males and 202 females) mature African American skeletal remains from the Hamann-Todd Collection (Museum of Natural History, Cleveland, Ohio) were analyzed. The inclusion of both samples also facilitated an examination of geographical variation within and between populations.
The morphology of the 12th thoracic vertebra was investigated using stepwise regression and discriminate function analyses. The results demonstrate that 82% of South African males and 83% of South African females correctly classify for sex using this methodology. Among the sample of African American males and females, a total of 86% were correctly classified. Though it appears that age-related changes have little effect on the level of correct classification of sex in the African American sample, age-related changes reduced correct classification in the South African sample. Although limited to two samples, this study suggests that the 12th thoracic vertebra has potential for use in sex estimation, and further research on additional samples is warranted.